<template>
	<view style="background: #FFFFFF;">
		<!-- <view v-if="loading">
		</view> -->
		<canvas v-if="!tempFilePath" style="position: fixed;left: 0;top: 1000px;" :canvas-id="CanvasID" :style="{ width: canvasW + 'px', height: canvasH + 'px' }"></canvas>
		<view v-else style="position: relative;">
			<image lazy-load :src="tempFilePath" mode="widthFix" class="is-response" ></image>
			<button class="btn-style" @click.stop="toSave(tempFilePath)">保存图片</button>
		</view>
	</view>
</template>

<script>
	var _this;
	export default {
		name: 'cc-poster',
		props: {
			CanvasID: {//CanvasID 等同于 canvas-id
				Type: String,
				default: 'PosterCanvas'
			},
			imgSrc: {//展示图
				Type: String,
				default: ''
			},
			QrSrc: {//二维码
				Type: String,
				default: ''
			},
			Title: {//文本内容
				Type: String,
				default: '省钱兄'
			},
			TitleColor: {//标题颜色
				Type: String,
				default: '#333333'
			},
			LineType: {//标题显示行数 大于两行是否省略	（注超出2行显示会导致画布布局絮乱）
				Type: [String, Boolean],
				default: true
			},
			PriceTxt: {//价格值
				Type: String,
				default: ''
			},
			PriceColor: {//价格颜色
				Type: String,
				default: '#e31d1a'
			},
			OriginalTxt: {//原价值
				Type: String,
				default: ''
			},
			OriginalColor: {//默认颜色（如原价与扫描二维码颜色）
				Type: String,
				default: '#b8b8b8'
			},
			Width: {//画布宽度  (高度根据图片比例计算 单位upx)
				Type: String,
				default: 750
			},
			CanvasBg: {//canvas画布背景色
				Type: String,
				default: '#ffffff'
			},
			Referrer: {//推荐人信息
				Type: String,
				default: '购买商品'
			},
			ViewDetails: {//描述提示文字
				Type: String,
				default: '长按或扫描识别二维码'
			}
		},
		data() {
			return {
				loading: false,
				tempFilePath: '',
				canvasW: 0,
				canvasH: 0,
				canvasImgSrc: '',
				ctx: null
			};
		},
		methods: {
			toSave(url) {
				console.log("长按开始");
				this.$emit('savebtn',url);
				//#ifndef H5
				// uni.getImageInfo({
				// 	src: url,
				// 	success: function(image) {
				// 		console.log('图片信息：', JSON.stringify(image));
				// 		uni.saveImageToPhotosAlbum({
				// 			filePath: image.path,
				// 			success: function() {
				// 				console.log('save success');
				// 				uni.showToast({
				// 					title: '海报已保存相册',
				// 					icon: 'success',
				// 					duration: 2000
				// 				});
				// 			}
				// 		});
				// 	}
				// });
				//#endif
			},
			async OnCanvas() {
				this.loading = true;
				
				// this.$queue.showLoading('海报生成中...');
				_this.ctx = uni.createCanvasContext(_this.CanvasID, this);
				const C_W = uni.upx2px(_this.Width), //canvas宽度
					C_P = uni.upx2px(30), //canvas Paddng 间距
					C_Q = uni.upx2px(150); //二维码或太阳码宽高
				let _strlineW = 0; //文本宽度
				let _imgInfo = await _this.getImageInfo({
					imgSrc: _this.imgSrc
				}); //广告图
				console.log('图片信息0：', JSON.stringify(""));
				
				let _QrCode = await _this.getImageInfo({
					imgSrc: _this.QrSrc
				}); //二维码或太阳码
				
				console.log('图片信息1：', JSON.stringify(""));
				
				let r = [_imgInfo.width, _imgInfo.height];
				let q = [_QrCode.width, _QrCode.height];
				let imgW = C_W - C_P * 2;
				if (r[0] != imgW) {
					r[1] = Math.floor((imgW / r[0]) * r[1]);
					r[0] = imgW;
				}
				if (q[0] != C_Q) {
					q[1] = Math.floor((C_Q / q[0]) * q[1]);
					q[0] = C_Q;
				}
				_this.canvasW = C_W;
				_this.canvasH = r[1] + q[1] + 128;
				_this.ctx.setFillStyle(_this.CanvasBg); //canvas背景颜色
				_this.ctx.fillRect(0, 0, C_W, _this.canvasH); //canvas画布大小

				//添加图片展示
				_this.ctx.drawImage(_imgInfo.path, C_P, C_P, r[0], r[1]);
				//添加图片展示 end

				//设置文本
				_this.ctx.setFontSize(uni.upx2px(32)); //设置标题字体大小
				_this.ctx.setFillStyle(_this.TitleColor); //设置标题文本颜色
				let _strLastIndex = 0; //每次开始截取的字符串的索引
				let _strHeight = r[1] + C_P * 2 + 10; //绘制字体距离canvas顶部的初始高度
				let _num = 1;
				for (let i = 0; i < _this.Title.length; i++) {
					_strlineW += _this.ctx.measureText(_this.Title[i]).width;
					if (_strlineW > r[0]) {
						if (_num == 2 && _this.LineType) {
							//文字换行数量大于二进行省略号处理
							_this.ctx.fillText(_this.Title.substring(_strLastIndex, i - 8) + '...', C_P, _strHeight);
							_strlineW = 0;
							_strLastIndex = i;
							_num++;
							break;
						} else {
							_this.ctx.fillText(_this.Title.substring(_strLastIndex, i), C_P, _strHeight);
							_strlineW = 0;
							_strHeight += 20;
							_strLastIndex = i;
							_num++;
						}
					} else if (i == _this.Title.length - 1) {
						_this.ctx.fillText(_this.Title.substring(_strLastIndex, i + 1), C_P, _strHeight);
						_strlineW = 0;
					}
				}
				//设置文本 end
				//设置价格
				_strlineW = C_P;
				_strHeight += uni.upx2px(60);
				if (_num == 1) {
					_strHeight += 20; //单行标题时占位符
				}
				if (_this.PriceTxt != '') {
					//判断是否有销售价格
					_this.ctx.setFillStyle(_this.PriceColor);
					_this.ctx.setFontSize(uni.upx2px(38));
					_this.ctx.fillText('￥' + _this.PriceTxt, _strlineW, _strHeight); //商品价格
					_strlineW += _this.ctx.measureText('￥' + _this.PriceTxt).width + uni.upx2px(10);
				}
				// #ifdef H5
				// #endif
				if (_this.PriceTxt != '' && _this.OriginalTxt != '') {
					//判断是否有销售价格且原价
					_this.ctx.setFillStyle(_this.OriginalColor);
					_this.ctx.setFontSize(uni.upx2px(24));
					_this.ctx.fillText(_this.OriginalTxt, _strlineW, _strHeight); //商品原价
				}
				_this.ctx.strokeStyle = _this.OriginalColor;
				_this.ctx.moveTo(_strlineW, _strHeight - uni.upx2px(10)); //起点
				_this.ctx.lineTo(_strlineW + _this.ctx.measureText(_this.OriginalTxt).width, _strHeight - uni.upx2px(10)); //终点
				_this.ctx.stroke();
				//设置价格 end

				//添加二维码
				_strHeight += uni.upx2px(20);
				_this.ctx.drawImage(_QrCode.path, r[0] - q[0] + C_P, _strHeight, q[0], q[1]);
				//添加二维码 end

				//添加推荐人与描述
				_this.ctx.setFillStyle(_this.TitleColor);
				_this.ctx.setFontSize(uni.upx2px(30));
				_this.ctx.fillText(_this.Referrer, C_P, _strHeight + q[1] / 2);
				_this.ctx.setFillStyle(_this.OriginalColor);
				_this.ctx.setFontSize(uni.upx2px(24));
				_this.ctx.fillText(_this.ViewDetails, C_P, _strHeight + q[1] / 2 + 20);
				//添加推荐人与描述 end
				//延迟后渲染至canvas上
				setTimeout(function() {
					_this.ctx.draw(true, ret => {
						uni.hideLoading();
						_this.getNewImage();
					});
				}, 600);
			},
			async getImageInfo({
				imgSrc
			}) {
				return new Promise((resolve, errs) => {
					uni.getImageInfo({
						src: imgSrc,
						success: function(image) {
							resolve(image);
						},
						fail(err) {
							errs(err);
							
							uni.showToast({
								title: '海报生成失败',
								mask: false,
								duration: 2000,
								icon: "none"
							});
							uni.hideLoading()
						}
					});
				});
			},
			getNewImage() {
				uni.canvasToTempFilePath({
						canvasId: _this.CanvasID,
						quality: 1,
						complete: res => {
							_this.tempFilePath = res.tempFilePath;
							_this.$emit('success', res);
							_this.loading = false;
						
							uni.showToast({
								title: '生成海报成功',
								mask: false,
								duration: 2000,
								icon: "none"
							});
							uni.hideLoading();
						}
					},
					this
				);
			}
		},
		mounted() {
			_this = this;
			this.OnCanvas();
		}
	};
</script>

<style>
	.is-response {
		border-radius: 20rpx;
	}
	.btn-style {
		margin: 40rpx auto;
		padding: 0;
		line-height: 70rpx;
		background-color: #FF9143;
		color: #FFF;
		font-size: 28rpx;
		border-radius: 50rpx;
		width: 210rpx;
		position: absolute;
		left: 0;
		right: 0;
		bottom: -120rpx;
	}
</style>
